#define _CRT_SECURE_NO_WARNINGS 1
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef pair<int, int> PII;
void solve()
{
	int n, k;
	cin >> n >> k;
	vector<PII> task;
	for (int i = 0; i < n; i++)
	{
		int a, b;
		cin >> a >> b;
		task[i] = { a, b };
	}
	sort(task.begin(), task.end());
	int s = 0;
	for (int i = 0; i < n; i++)
	{
		if (task[i].first * k - s < 0)
		{
			cout << "No" << endl;
			return;
		}
		else {
			s += task[i].second;
		}
	}
	cout << "Yes" << endl;
}
int main()
{
	int t;
	cin >> t;
	while (t--)
		solve();
	return 0;
}